1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
/*
* Copyright (C) 2012 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "platform/audio/AudioFIFO.h"
#if ENABLE(WEB_AUDIO)
namespace blink {
AudioFIFO::AudioFIFO(unsigned numberOfChannels, size_t fifoLength)
: m_fifoAudioBus(AudioBus::create(numberOfChannels, fifoLength))
, m_fifoLength(fifoLength)
, m_framesInFifo(0)
, m_readIndex(0)
, m_writeIndex(0)
{
}
void AudioFIFO::consume(AudioBus* destination, size_t framesToConsume)
{
bool isGood = destination && (framesToConsume <= m_fifoLength) && (framesToConsume <= m_framesInFifo) && (destination->length() >= framesToConsume);
ASSERT(isGood);
if (!isGood)
return;
// Copy the requested number of samples to the destination.
size_t part1Length;
size_t part2Length;
findWrapLengths(m_readIndex, framesToConsume, part1Length, part2Length);
size_t numberOfChannels = m_fifoAudioBus->numberOfChannels();
for (size_t channelIndex = 0; channelIndex < numberOfChannels; ++channelIndex) {
float* destinationData = destination->channel(channelIndex)->mutableData();
const float* sourceData = m_fifoAudioBus->channel(channelIndex)->data();
bool isCopyGood = ((m_readIndex < m_fifoLength)
&& (m_readIndex + part1Length) <= m_fifoLength
&& (part1Length <= destination->length())
&& (part1Length + part2Length) <= destination->length());
ASSERT(isCopyGood);
if (!isCopyGood)
return;
memcpy(destinationData, sourceData + m_readIndex, part1Length * sizeof(*sourceData));
// Handle wrap around of the FIFO, if needed.
if (part2Length)
memcpy(destinationData + part1Length, sourceData, part2Length * sizeof(*sourceData));
}
m_readIndex = updateIndex(m_readIndex, framesToConsume);
ASSERT(m_framesInFifo >= framesToConsume);
m_framesInFifo -= framesToConsume;
}
void AudioFIFO::push(const AudioBus* sourceBus)
{
// Copy the sourceBus into the FIFO buffer.
bool isGood = sourceBus && (m_framesInFifo + sourceBus->length() <= m_fifoLength);
if (!isGood)
return;
size_t sourceLength = sourceBus->length();
size_t part1Length;
size_t part2Length;
findWrapLengths(m_writeIndex, sourceLength, part1Length, part2Length);
size_t numberOfChannels = m_fifoAudioBus->numberOfChannels();
for (size_t channelIndex = 0; channelIndex < numberOfChannels; ++channelIndex) {
float* destination = m_fifoAudioBus->channel(channelIndex)->mutableData();
const float* source = sourceBus->channel(channelIndex)->data();
bool isCopyGood = ((m_writeIndex < m_fifoLength)
&& (m_writeIndex + part1Length) <= m_fifoLength
&& part2Length < m_fifoLength
&& part1Length + part2Length <= sourceLength);
ASSERT(isCopyGood);
if (!isCopyGood)
return;
memcpy(destination + m_writeIndex, source, part1Length * sizeof(*destination));
// Handle wrap around of the FIFO, if needed.
if (part2Length)
memcpy(destination, source + part1Length, part2Length * sizeof(*destination));
}
m_framesInFifo += sourceLength;
ASSERT(m_framesInFifo <= m_fifoLength);
m_writeIndex = updateIndex(m_writeIndex, sourceLength);
}
void AudioFIFO::findWrapLengths(size_t index, size_t size, size_t& part1Length, size_t& part2Length)
{
ASSERT_WITH_SECURITY_IMPLICATION(index < m_fifoLength && size <= m_fifoLength);
if (index < m_fifoLength && size <= m_fifoLength) {
if (index + size > m_fifoLength) {
// Need to wrap. Figure out the length of each piece.
part1Length = m_fifoLength - index;
part2Length = size - part1Length;
} else {
// No wrap needed.
part1Length = size;
part2Length = 0;
}
} else {
// Invalid values for index or size. Set the part lengths to zero so nothing is copied.
part1Length = 0;
part2Length = 0;
}
}
} // namespace blink
#endif // ENABLE(WEB_AUDIO)
|
